Blockchain Ecosystem and Use Cases BDC Practice Questions (Page 8)

Questions 36–40

1. 36foundation · easy

   Which regulatory concern is most directly associated with the use of blockchain for financial transactions?

   • AIntellectual property rights for smart contract code
   • BData storage limits on the blockchain
   • CNetwork latency requirements
   • DAnti-Money Laundering (AML) and Know Your Customer (KYC) compliance
   Reveal Solution Discussion Select an answer first
2. 37application · medium

   A startup is building a decentralized voting dApp where users must be able to verify that their vote was counted without revealing who they voted for. The team plans to use a public blockchain and store the vote on-chain. Which additional design choice is most important to meet the privacy requirement?

   • AStore votes off-chain and only record a hash of the vote on-chain.
   • BUse a zero-knowledge proof (e.g., zk-SNARK) to submit a proof of a valid vote without revealing the vote content.
   • CUse a permissioned blockchain with a whitelist of registered voters to ensure only authorized users can vote.
   • DEncrypt each vote with the voter's private key before submitting it to the smart contract.
   Reveal Solution Discussion Select an answer first
4. 38foundation · easy

   Which consensus mechanism requires participants to prove ownership of a certain amount of cryptocurrency to validate transactions?

   • APractical Byzantine Fault Tolerance (PBFT)
   • BProof of Stake (PoS)
   • CDelegated Proof of Stake (DPoS)
   • DProof of Work (PoW)
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5. 39expert · hard · select all that apply

   A blockchain consortium is deciding between a proof-of-authority (PoA) and a delegated proof-of-stake (DPoS) consensus mechanism. They value high throughput, low energy consumption, and the ability to exclude malicious validators. However, they are concerned about centralization and regulatory scrutiny. Which of the following are true trade-offs to consider? (Select all that apply.)

   • ADPoS allows token holders to vote out validators, which can be more democratic but may lead to voter apathy and plutocracy
   • BRegulatory scrutiny is unaffected by the choice of consensus mechanism
   • CPoA relies on a fixed set of validators, which can be more centralized but allows for easy exclusion of bad actors
   • DPoA is always more decentralized than DPoS because it does not involve voting
   • EBoth PoA and DPoS are energy-efficient compared to proof-of-work
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6. 40foundation · easy

   In a blockchain governance model, what is the primary purpose of on-chain governance?

   • ATo enable miners to decide which transactions to include in a block
   • BTo provide a legal framework for smart contracts
   • CTo ensure that all nodes have the same version of the software
   • DTo allow stakeholders to vote on protocol changes directly through the blockchain
   Reveal Solution Discussion Select an answer first